Flying in the face of the "telepathic twins" stereotype, Tegan and Sara Quin have always been independent, easily distinguishable songwriters who complement and clash with one another in equal doses. It wasn't until they started work on their sixth studio album — last year's Sainthood — that the sisters tried to co-write some songs for the first time. As it turned out, only one of those collaborative efforts made the record. But for Tegan and Sara, it was an important step in what has been a vibrant, ever-evolving indie-rock career.

"I think you sort of create a certain way of working over time," says Sara. "Tegan and I always just gravitated toward working on songs independently. It's a pretty intimate process, so it's not always easy to bring someone else into it. And probably more importantly, when we have time off, we're in different cities [Sara lives in Montreal, Tegan lives in Vancouver]. But I definitely think that, as we've gotten older and more confident in our songwriting, it just becomes an obvious thing to expand that process and include each other more. And so far, it's been really cool. After writing on our own for so many years, it's exciting to change things up a bit."

Embracing change has played a huge role in the Quin twins' rise to international stardom over the past decade, starting with their shift from spunky teenage folk-pop into more sophisticated — but no less spunky — synth-rock on 2004's So Jealous. That album and its standout track "Walking With a Ghost" helped transform Tegan and Sara from a pair of young hopeless romantics into one of indie rock's marquee acts — a role that consequently cast them as responsible businesswomen as well.

"When Tegan and I first started touring, we didn't really understand the music industry at all," says Sara. "As 19-year-olds, we were like wayward youth — teenage runaways on the Greyhound bus going across Canada, playing to 20 people in a sports bar. It was a serious achievement if we managed to find our Econo Lodge and check in. And now, it's like we've built this whole little world — this business we run. We have our own touring company, our own merchandising company, various full-time employees and managers. And on top of that, we're trying to write songs and record albums! But it's amazing. Every year, our business grows and we branch out into new things [Sainthood, for example, was supported by the release of an exclusive three-book set, ON, IN, AT]. I mean, we just thrive on making shit. And I hope it's all quality shit."

Earning nearly unanimously positive reviews and a career-best No. 21 spot on Billboard's album chart, Sainthood certainly qualifies as "quality shit." It may be Tegan and Sara's defining moment as artists up to this point. While the co-writing experiment wasn't a huge success, both sisters delivered their A-games individually on the album, and producer Chris Walla (who's a member of Death Cab for Cutie) helped light a spark by trying a new approach in the studio, reducing overdubs and recording the band live for a more immediate, concert-like sound.

"I feel like, since the first show we did on this album, the response to the new material has just been so awesome," says Sara, noting that Sainthood seems to require far less "growing time" than the band's previous album, 2007's The Con. "When I think about The Con — it was a really dark record and a really intense time. Everything about the experience was positive, but there's definitely a heaviness to it. Whereas with Sainthood, it feels really light. It doesn't feel like I'm hanging onto it as much. It happened, it was pretty positive, the record's out and I don't feel like I need therapy."

While she can't speak for Tegan, Sara feels like Sainthood benefited from a little more maturity and emotional balance — even if the lyrics of standout tracks like "Alligator" and "Hell" still appeal to the melodramatic teen audience they've always appealed to.

"It definitely feels easier to write when there's a middle ground," she says. "When I'm utterly, profoundly depressed, I don't write. And when I'm really, really psycho happy, I don't write. It's usually when something really remarkable has happened in my life or I'm on the eve of something really bad happening — whether it's with a relationship or whatever — that's when I feel the most prolific. Like right now, I would say that I'm in this weird, balanced time in my life where kind of nothing great and nothing bad is happening in my personal life. So I feel much more introspective."